Traditionally, manufacturers of agricultural tractors make one type of tractor for row-crop work and another for serving as the power unit for self-propelled implements, such as a windrowers or mower-conditioners, for example. Standard agricultural tractors are often equipped with an operator's station housed within a cab which is situated between a pair of rear drive wheels of the tractor and facing forward toward an engine of the tractor, while the power unit for a self-propelled implement, such as a windrower, is commonly equipped with a cab located between a pair of front drive wheels and faces in a forward direction away from the engine so that the operator has excellent visibility of front-mounted equipment. The physical appearance of the tractor and power unit are generally similar, with the primary difference being the direction the vehicle is driven in normal forward operation. The manufacture of two different tractors leads to increased costs, especially if one or the other enjoys an economy of scale due to the number of units sold.
Heretofore, it has been known to provide a tractor equipped with a cab in which the seat, steering wheel and control console are mounted for swiveling about a vertical axis between a first position wherein the operator faces the engine and operates the tractor for towing implements, and a second position, wherein the operator faces away from the engine and operates the tractor in good view of front-mounted equipment. However, this known tractor has a hydrostatic transmission which may be easily reversed in operation without a degradation of function, i.e., the operating characteristics of the transmission remain the same for propelling the tractor in opposite directions. This is in contrast to a tractor equipped with a gear transmission wherein mating gears often have their greatest load carrying capacity only when driven so as to propel the tractor in one direction. An example of a prior art tractor which may be operated in a bi-directional manner is disclosed in U.S. Pat. No. 4,059,171.
Therefore, the problem to be solved is that of being able to use substantially all of the components of a standard, row-crop tractor in the manufacture of a dedicated, self-propelled implement tractor which has a forward operation mode that is the reverse of that of a standard row-crop tractor.